ME 516 FLUID POWER CONTROL
FALL 2015-2016
TERM PROJECT
Modeling, Simulation and Control of an Electro Hydrostatic
Actuator
In your term project, you are expected to model, simulate and control an Elector Hydrostatic
Actuator (EHA). A typical hydraulic circuit architecture of an EHA is shown in Figure 1.a. In
this circuit a servo motor driven constant displacement pump regulates the flow rate through
the hydraulic actuator (symmetric, double-rod), and a hydraulic accumulator compensates the
leakage losses of the hydraulic pımp.
Figure 1 a) Sample hydraulic circuit of and EHA, [1]
Your EHA should satisfy the following design criteria. You are free to select the maximum
force and speed of the EHA. You should size your actuator and select the hydraulic and electric
components according to these criteria’s. You should provide the catalogs/manuals of the
selected components. Unfortunately, some information like the leakage characteristics of the
pump is not available by the manufacturers; therefore you are free to construct your own leakage
characteristics. Note that the leakage characteristic should be compatible with the pumps
hydraulic and mechanical efficiency curves.

Stroke: in between 100-200 mm

Maximum output force: in between 10-20 kN

Maximum working pressure: 21 MPa

Maximum speed: in between 300-500 mm/s

Maximum overshoot : 20%

Moving mass: 20 kg

Stiffness at 5 Hz sinusoidal external load: 25 kN/mm (minimum)

Bandwidth (-3dB requirement), 10 Hz (minimum)

Accumulator line pressure 0.3 MPa
Project Reports

Roport 1-a (Soft Copy) (Due Date: 14.12.2015)
-
Literature survey: Give an overview of hydraulic circuits used in EHA.
-
Size your hydraulic system and select required components.
-
From the catalogs/manuals of the components that you are provided, determine the
model parameters.

Report 2 (Soft Copy) - MATLAB®/Simulink® (Due Date: 24.12.2015)
-
Provide a physical model in your report and clearly specify all your assumptions.
-
Write all elemental and structural equations.
-
Construct a numerical simulation model in MATLAB®/Simulink® using these
equations.

Evaluate your model by performing open-loop simulations.
Report 3 – (Soft Copy) SimHydraulics® (Due Date: 04.01.2016)
-
Construct a simulation model by using SimHydraulics®.
-
Evaluate your model by performing open-loop simulations.
-
In this report, you should also compare the open-loop responses obtained from
Simulink® and SimHydraulics® models and comment on the results.

Final Report – Report 1 + Report 2 + Controller Design (Hard Copy) (Due Date:
Final Examination Date)
-
Design a closed-loop position controller and provide the details of the design steps
that you have followed in your report. You are free to select any type of controller
design methodology (Classical PID controller, state-space controller, non-linear
controllers, etc.).
-
Evaluate the closed-loop performance of the system with the controller you designed
by simulating your mathematical models. Comment on the results; whether the
expected performance is obtained.
-
You should also prepare and make a presentation on the final examination date and
submit a paper related to your term project.
Some research papers related with the subject,
[1]
S. Frischemeier, “Electrohydrostatic Actuators for Aircraft Primary Flight ControlTypes, Modelling and Evaluation,” in SICFP’97, Proceedings, 5th Scandinavian International
Conference on Fluid Power, 1997, pp. 1–16.
[2]
S. Habibi and A. Goldenberg, “Design of a New High Performance ElectroHydraulic
Actuator,” IEE/ASME Proc. Mechatronics, vol. 50, no. 2, pp. 158–164, 2000.
[3]
M. a. El Sayed and S. Habibi, “Inner-Loop Control for Electro-Hydraulic Actuation
Systems,” J. Dyn. Syst. Meas. Control, vol. 134, no. 1, p. 014501, 2011.
[4]
S. Kukonen and E. Makinen, “Performance of a pump controlled asymmetric actuator a comparision of different control methods,” in Proceedings of the ASME/BATH Syposium on
Fluid Power & Motion Control, 2014.
[5]
V. Karanović, M. Jocanović, and K. Hall, “Review of Development Stages in the
Conceptual Design of an Electro-Hydrostatic Actuator for Robotics A Review of EHA
Development,” vol. 11, no. 5, pp. 59–79, 2014.
[6]
S. R. Habibi and G. Singh, “Derivation of Design Requirements for Optimization of a
High Performance Hydrostatic Actuation System,” Int. J. Fluid Power, vol. 1, no. 2, pp. 11–27,
2000.
[7]
M. G. P. M. G. Park, S. H. P. S. H. Park, J. S. K. J. S. Kim, and H. G. L. H. G. Lee,
“Modeling and control and electro hydrostatic actuator systems,” 2009 Iccas-Sice, pp. 3003–
3008, 2009.
[8]
C. Greissner and U. Carl, “Control of an Electro-Hydrostatic Actuation System for the
Nose Landing Gear of an, All Electric Aircraft”,” Power, 2004.
[9]
J. Andersson, P. Krus, K. Nilsson, and K. Strock, “Modelling Electro-Hydrostatic of
Heat Generation Systems,” in 4th JHPS International Symposium, 1999, no. C, pp. 537–542.
[10] M. Pachter, C. H. Houpis, and K. Kang, “Modelling and Control of an Electro Hydrostatic
Actuator,” Int. J. Robust Nonlinear Control, vol. 7, pp. 591–608, 1997.
[11] F. Barbosa and L. A. Filho, “An analysis of electro – hydrostatic actuators in more
electric aircrafts,” Divisao de Engenharia Mecanica, Instituto Technologica da Aeronautica,
2008.
ME 516 FLUID POWER CONTROL
FALL 2015-2016
TERM PROJECT
Modeling, Simulation and Control of a Hydrostatic Drive System
In your term project, you are expected to model, simulate and control a hydrostatic drive system
for a mobile machine. The schematic view of the hydrostatic transmission system is shown in
Figure 1. The hydrostatic transmission system consists of a variable displacement hydraulic
pump and variable displacement hydraulic motor. The pump is driven by the internal
combustion engine, and the hydraulic motor is connected to a gear box in series.
Figure 1 Hydrostatic drive system concept , [1]
The system is assumed to be used in a railway application. It is desired to climb a 4-degree
ramp with 20 kmph speed with 10e3kg mass. The gear-box ratio is constant and is equal to 5.
The wheel diameters are 350mm (can be changed in your design). You are desired to select and
internal combustion engine (ICE), determine the operation speed (it will be constant ex. 2250
rpm) and then size the hydrostatic transmission system and construct a simulation model.
The ICE speed is constant, the pump displacement is determined by the operator input and the
hydraulic motor displacement should be adjusted according to the loading conditions.
Project Reports

Roport 1-a (Soft Copy) (Due Date: 14.12.2015)
-
Literature survey: Give an overview of hydraulic circuits. (you may check Rexroth
AA4VG and A6VM, or Rexroth A41CT)
-
Size your hydraulic system and select required components.
-
From the catalogs/manuals of the components that you are provided, determine the
model parameters.

Report 2 (Soft Copy) - MATLAB®/Simulink® (Due Date: 24.12.2015)
-
Provide a physical model in your report and clearly specify all your assumptions.
-
Write all elemental and structural equations.
-
Construct a numerical simulation model in MATLAB®/Simulink® using these
equations.

Evaluate your model by performing open-loop simulations.
Report 3 – (Soft Copy) SimHydraulics® (Due Date: 04.01.2016)
-
Construct a simulation model by using SimHydraulics®.
-
Evaluate your model by performing open-loop simulations.
-
In this report, you should also compare the open-loop responses obtained from
Simulink® and SimHydraulics® models and comment on the results.

Final Report – Report 1 + Report 2 + Controller Design (Hard Copy) (Due Date:
Final Examination Date)
-
Design a controller for the hydraulic motor swash plate angle and provide the details
of the design steps that you have followed in your report.
-
You should also prepare and make a presentation on the final examination date and
submit a paper related to your term project.
Some research papers related with the subject,
[1]
K.-E. Rydberg, “Hydrostatic Drives in Heavy Mobile Machinery – New Concepts and
Development Trends,” SAE Trans., vol. 107, no. 1382, pp. 232–238, 1997.